中国农业科学 ›› 2017, Vol. 50 ›› Issue (11): 2166-2178.doi: 10.3864/j.issn.0578-1752.2017.11.021

所属专题: 玉米栽培研究专刊

• 土壤耕作与施肥 • 上一篇    下一篇

夏玉米根系与土壤硝态氮空间分布吻合度对水氮处理的响应

尹飞1,王俊忠2,孙笑梅2,李洪岐3,付国占1,裴瑞杰4,焦念元1

 
  

  1. 1河南科技大学农学院,河南洛阳471023;2河南省土壤肥料站,郑州450002;3河南省农学会,郑州 450002;4南阳农业职业学院,河南南阳 473000
  • 收稿日期:2016-08-05 出版日期:2017-06-01 发布日期:2017-06-01
  • 通讯作者: 王俊忠,E-mail:wangjz168@vip.sina.com
  • 作者简介:尹飞,E-mail:feiyin@yeah.net
  • 基金资助:
    科技部粮食丰产科技工程项目(2013BAD07B07)、河南科技大学学科提升振兴A计划项目(13660002)、河南科技大学博士科研启动基金(09001273)

Response of Spatial Concordance Index Between Maize Root and Soil Nitrate Distribution to Water and Nitrogen Treatments

YIN Fei1, WANG JunZhong2, SUN XiaoMei2, LI HongQi3, FU GuoZhan1, Pei RuiJie4, JIAO NianYuan1   

  1. 1College of Agronomy, Henan University of Science and Technology, Luoyang 471023, Henan; 2Soil and Fertilizer Station of Henan Province, Zhengzhou 450002; 3Henan Association of Agricultural Science Societies, Zhengzhou 450002; 4Nanyang Vocational College of Agriculture, Nanyang 473000, Henan
  • Received:2016-08-05 Online:2017-06-01 Published:2017-06-01

摘要: 【目的】根系是玉米吸收氮素营养的主要器官。在大田条件下,对夏玉米根系生长分布、根系与土壤硝态氮空间吻合度对不同水氮处理的响应,以及根系与土壤硝态氮空间吻合度指标的有效性进行研究,用以了解其时空分布及与土壤氮分布的吻合情况对玉米氮素吸收利用的影响。【方法】2011—2015年,设置不灌水+不施氮(W0N0)、不灌水+300 kg N·hm-2W0N1)、不灌水+360 kg N·hm-2W0N2)、大喇叭口期灌水+不施氮(W1N0)、大喇叭口期灌水+300 kg N·hm-2W1N1)、大喇叭口期灌水+360 kg N·hm-2W1N2)共6个水氮处理。各施氮处理下拔节期施氮30%、大喇叭口期施氮70%。大喇叭口期灌水量为750 m3·hm-2。在2015年玉米生长季,分别于玉米拔节期、大喇叭口期、吐丝期、吐丝后20 d和成熟期在玉米种植行和行间采集0—50 cm土体样品(每10 cm一层),测定夏玉米根长密度、根干重密度、土壤硝态氮含量,并计算根系与土壤硝态氮空间吻合度。在成熟期采集植株样品,分析玉米氮素吸收量。【结果】随着玉米生育进程,种植行和行间0—50 cm土壤剖面夏玉米根长密度、根干重密度和硝态氮含量均表现出先升高后降低的趋势,根长密度和根干重密度峰值出现在吐丝后20 d,而土壤硝态氮含量峰值出现在大喇叭口期。在0—360 kg·hm-2的范围内,夏玉米根长密度和吐丝期之前土壤硝态氮含量随施氮量的增加而增加,但玉米根干重密度和吐丝期之后土壤硝态氮含量先升高后降低,峰值出现在施氮300 kg·hm-2处理。大喇叭口期灌水可以提高夏玉米生育后期根长密度和根干重密度,但降低了土壤硝态氮含量。随着土层加深,种植行夏玉米根长密度与土壤硝态氮空间吻合度(RLD1-N)以及根干重密度与土壤硝态氮空间吻合度(RWD1-N)总体呈降低趋势,行间夏玉米根长密度与土壤硝态氮空间吻合度(RLD2-N)以及根干重密度与土壤硝态氮空间吻合度(RWD2-N)总体呈先增加后降低趋势,峰值出现在10—30 cm土层。随着玉米生育进程,各土层RLD1-N、RWD1-N和RWD2-N以及0—40 cm土层RLD2-N呈先升高后降低变化趋势。与不施氮处理相比,施用氮肥提高了RLD1-N、RLD2-N、RWD1-N和RWD2-N。施氮量从300 kg·hm-2增加至360 kg·hm-2时,降低了0—30 cm土层RLD2-N、0—20 cm土层RWD1-N以及拔节至吐丝期间RLD1-N和0—20 cm土层RWD2-N,提高了40—50 cm土层RLD2-N、20—50 cm土层RWD1-N以及吐丝期之后的RLD1-N和RWD2-N。夏玉米种植行和行间根长密度和根干重密度与其硝态氮含量的吻合度与产量极显著正相关,但与氮素利用效率极显著负相关,且其相关性优于根长密度和根干重密度与产量及氮素利用效率的相关性。【结论】在大田条件下,施用氮肥可以提高夏玉米根长密度、根干重密度、土壤硝态氮含量以及夏玉米根系与土壤硝态氮空间吻合度。但施氮量超过300 kg·hm-2时会降低夏玉米生育前期上部土层的夏玉米根系与土壤硝态氮空间吻合度。根系与土壤硝态氮空间吻合度可以作为研究夏玉米氮素利用效率的有效指标。

关键词: 玉米, 根长密度, 根干重密度, 土壤硝态氮含量, 空间吻合度

Abstract: 【Objective】Root is a major organ of maize for the absorption of soil nitrogen nutrition. The spatial concordance index between maize root and soil nitrogen distribution might have an influence on nitrogen uptake and utilization of maize. The purposes of this study were: (1) to analyze the effects of water and nitrogen treatments on maize root distribution and the spatial concordance index between maize root and soil nitrate content; (2) to determine the effectiveness of spatial concordance index between maize root and soil nitrate content. 【Method】 From 2011 to 2015, the experiment was set in six treatments, including W0N0 (0), W0N1 (0+300 kg N·hm-2), W0N2 (0+360 kg N·hm-2), W1N0 (750 m3·hm-2 +0), W1N1 (750 m3·hm-2+ 300 kg N·hm-2), and W1N2 (750 m3·hm-2+ 360 kg N·hm-2), in which irrigation occurred at spike formation stage, and nitrogen applied at jointing stage (30%N) and spike formation stage (70%N). In maize growing season of 2015, soil samples were collected in and between maize planting lines at jointing, spike formation, silking, 20 days after silking, and mature stage. Root length density (RLD) and root dry weight density (RWD), soil nitrate content, spatial concordance index between root and soil nitrate content, and nitrogen absorption were analyzed. 【Result】 With the development of maize growth process, both in and between the lines of maize, RLD, RWD, and soil nitrate content increased first and then decreased. The maximum values of RLD and RWD occurred in 20 days after silking, and the maximum value of soil nitrate content occurred at spike formation stage. In the range of 0-360 kg·hm-2, with the increasing of nitrogen application rate, maize RLD and soil nitrate content before silking stage kept increasing. However, maize RWD and soil nitrate content after silking stage increased first and then decreased, and the maximum value occurred in 300 kg·hm-2 nitrogen application treatment. At the late stage of maize growth, irrigation increased RLD and RWD, but decreased soil nitrate content. With the increasing of soil layer depth, RLD1-N (the spatial concordance index between RLD and soil nitrate content at the maize planting line) and RWD1-N (the spatial concordance index between RWD and soil nitrate content at the maize planting line) showed a decreasing trend, RLD2-N and RWD2-N showed a trend of increasing first and then decreasing, the maximum value occurred in 10-30 cm soil layer. With the development of maize growth process, RLD1-N, RWD1-N, and RWD2-N , and RLD2-N in 0-40 cm soil layer showed a trend of increasing first and then decreasing. Compared with no nitrogen treatment, nitrogen applications significantly increased RLD1-N, RLD2-N, RWD1-N and RWD2-N. When increasing nitrogen from 300 kg·hm-2 to 360 kg·hm-2, the RLD2-N of 0-30 cm soil layer, the RWD1-N of 0-20 cm soil layer, the RLD1-N from jointing to silking stage, and the RWD2-N of 0-20 cm soil layer were decreased; and the RLD2-N of 40-50 cm soil layer, the RWD1-N of 20-50 cm soil layer, the RLD1-N and RWD2-N after silking stage were increased. RLD1-N, RLD2-N, RWD1-N, RWD2-N had a remarkable correlation with maize yield and nitrogen use efficiency, which the correlation coefficient was higher than between root length density, root weight density and maize yield, nitrogen use efficiency. 【Conclusion】Under field conditions, nitrogen fertilizer application increased RLD, RWD, RLD1-N, RLD2-N, RWD1-N and RWD2-N, but decreased RWD, RLD1-N before silking, RWD2-N, RLD2-N and RWD1-N when nitrogen fertilizer application exceeded 300 kg·hm-2. The spatial concordance index between root and soil nitrate can be a effective index to assess nitrogen use efficiency of maize.

Key words: maize, root length density, root dry weight density, soil nitrate content, spatial concordance index